Sec. 6. BOND. The Tax Collector, before entering upon the duties of his office, shall enter into a bond, with two (2) or more good and sufficient sureties, or surety bond, for the protection of said equalization fund, said bond to be made payable to the County Board of School Trustees, and to be made in a sum not less than double the amount of money which he may have in his possession of said fund at any time. The amount of said bond shall be fixed by the County Board of School Trustees. The County Board shall require a similar bond of any and all other persons or corporations in whose possession such funds may be kept.